coveted treasure mentioned in old-book catalogues, it
would be snapped up by another and never delight his eyes.
But such was not to be the case. In due time it came
(pages uncut) and then what keen delight was his as he
devoured page after page, marveling more and more at
the wonderful breadth and perspicacity of the presenta-
tion. Pasteur seemed alive in its pages, and Duclaux
not less alive. No book about a scientific man ever in-
terested him more, or could be written, it seemed, with a
more appreciative and discriminating touch. When the
last page was finished nothing was more natural, there-
fore, than to write on its margin: "The most useful book
I have read in a long time."

Going over these pages ten years later, the writer sees
no reason for modifying his first judgment. The next
impulse was to lend the book, and then to wish that it
might reach thousands of readers in a suitable English
dress. This idea disturbed his spirit so much that finally
he began a translation, dictating to a stenographer in the
odd minutes of a busy life. Later, it seemed better to
turn over a part of this work to an assistant. Eventu-
ally, about two-thirds of the rough draft from the French
was made by Florence Hedges. We then worked it over
together into its present English shape, but those who
can read it in the French are advised to do so, since, do
the best we could, Duclaux's wonderful idiomatic style
has lost somewhat in the translation.

If Pasteur be an incomparable genius, Duclaux, at
least, is his Boswell, but he is more than a mere Boswell
tagging around after a great man. He is himself a great
man. He has a genius of his own which burns with a very
clear flamer--a genius that penetrates and illuminates
whatever it touches, and this has made him an incompar-
able biographer, and one of an unusual kind. He is no
blind partisan or patriot. He thinks his own thoughts,

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